I'm working mapviewer in obiee 11g, do you know where and how i can increase the java heap space to avoid this error:
MAPVIEWER-06009: Error processing an FOI request. Root cause: FOIServlet: Java heap space

You'll have to check the OBIEE documentation or the OBIEE Product Assurance blog (see the entry for the obiee performance tuning guide) https://blogs.oracle.com/pa/
for the correct location and details.

However, I expect you do this by changing the entries for jrockit memory args in setDomainEnv.sh under user_projects/domains/bifoundation_domain/bin

increase min to 1024M and max to 2048M if your machine has enough memory available.